Parents afternoon

Today I am recovering from a particularly stressful parent teacher interview. It threw me completely as the pupil is bright and achieving well in my class, so I didn't expect the onslaught which began from both mother and child as soon as they sat down.
I just wish that I the effect of one positive comment would
It is amazing the effect that one such comment can have, sending you into an instant questioning of your own ability. Why were the comments from the other 12 positive parents and pupils not sufficient to cancel out these negative thoughts?